Magnetic resonance imaging of lumbar disc herniation. Comparison with myelography

Fifty-three patients with surgically confirmed lumbar disc herniation at 55 levels were studied retrospectively to compare the diagnostic accuracy of high-field strength surface coil magnetic resonance imaging (MRI) with that of myelography. Disc herniation was classified into three groups according to MRI findings, namely, unilateral single-disc herniation, central single-disc herniation, and multilevel disc herniation. Magnetic resonance imaging diagnosis of unilateral single-disc herniation was extremely reliable, so myelography was considered to be unnecessary. Conversely, MRI findings of central single-disc herniation and multilevel disc herniation were less definite, in that myelography was necessary in locating the disc causing symptoms.